This section provides background information related to the present disclosure which is not necessarily prior art.
Rotating tubular shafts or members are often used in various applications to transmit torque between members. For example, rotating tubular shafts can be used to transmit torque in automotive vehicle application via a drive shaft. Similarly, rotating tubular shafts can also be used to transmit torque in aeronautical or marine applications via a propeller shaft. Generally, in all applications, these rotating tubular shafts or members can be referred to as propeller shafts.
In many of the aforementioned applications, however, the rotation and vibration of these tubular members can lead to undesirable noise, vibration, and/or harshness (NVH). The mechanism driving the shaft, such as a transmission/engine system can also generate noise and vibration which is carried, channeled and emanated by the propeller shaft. In both cases, the resulting NVH can then lead to unwanted discomfort by the vehicle occupants and potential damage due to vibrations.
Particularly in automotive applications, attempts have been made to damp such NVH through the use of liners or other members within the propeller shaft. Although such dampeners have performed reasonably well in absorbing propeller shaft vibrations, it has been found that they can have performance variations. It has also been found that conventional liners such as cardboard liner, although capable of performing some damping, may not provide sufficient damping required in today's applications.
Additionally and previously unrelated to damping of propeller shafts, there has been a recent need to reduce the overall weight of vehicles for improved fuel economy. To this end, it is particularly important to reduce the weight of rotating members because reduction of rotational mass is capable of providing additional efficiency benefits beyond that of simple weight reduction.
Accordingly, there is a need in the relevant art to provide a dampener for use in propeller shaft technology and other rotating tubular members that is capable of reducing noise, vibration, and harshness. Additionally, there is a need in the relevant art to provide a dampener for use in propeller shaft technology that is capable of reducing the mass of the propeller shaft. Still further, there exists a need in the relevant art to provide a dampener for use in propeller shaft technology that is capable of overcoming the deficiencies of conventional liners to provide improved reductions in noise, vibration, harshness, and weight.